Patent Literature 1 discloses a heat pump heating and hot-water system including a hot-water storage tank for storing hot water heated by a heat pump unit, a radiator for indoor heating by use of hot water heated by the heat pump unit, and a hot-water-supply heat exchanger consisting of a coil-form pipe provided in the hot-water storage tank. In this system, when hot water is supplied, feed-water is heated by the hot-water-supply heat exchanger in the hot-water storage tank to produce hot-water.